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Security report for 1und1.de

1&1 Telecom GmbH · Telecommunications · Germany

Low risk. 2 critical or high findings in Security headers and GDPR outside view.

Security score

79/100

Risk levelLow

0–100, higher is better. How it is calculated

1&1 Telecom GmbH is a major telecommunications provider in Germany offering a comprehensive range of internet and mobile telephony services. The company operates under the umbrella of United Internet AG and has a strong market presence with a focus on private and business customers. Their website reflects a professional and modern digital presence, leveraging advanced web technologies and a robust content management system (Neos CMS). The site is well-optimized for mobile devices and provides clear navigation and comprehensive service information. Security-wise, the website enforces HTTPS, employs secure form handling, and integrates reputable third-party analytics and marketing tools. Privacy compliance is well addressed with detailed policies and consent mechanisms, aligning with GDPR requirements. Overall, the website demonstrates a high level of professionalism, trustworthiness, and technical maturity, supporting the company's enterprise-level stature in the telecommunications sector.

Scanned

NIS2 and GDPR posture

GDPR outside view
85/ 100 · Low
Checks completed
7of 7

NIS2 Art. 21(2)

  1. (a) Risk analysis and security policies: Not visible from outside
  2. (b) Incident handling: One indicator
  3. (c) Business continuity, backups and crisis management: Not visible from outside
  4. (d) Supply chain security: Not visible from outside
  5. (e) Secure acquisition, development and maintenance, including vulnerability handling: Partly checked
  6. (f) Assessing the effectiveness of security measures: Not visible from outside
  7. (g) Cyber hygiene and security training: Not visible from outside
  8. (h) Cryptography and encryption: Partly checked
  9. (i) HR security, access control and asset management: One indicator
  10. (j) Multi-factor authentication and secured communications: Not visible from outside

This scan rated NIS2 with an earlier keyword method that is no longer shown; rescan for the per-article view. Risk management, continuity, supply chain, training, MFA, management oversight (Art. 20) and incident reporting (Art. 23) need internal evidence, and Guard cannot tell whether NIS2 applies to this organisation.

GDPR is indicative only, based on publicly visible signals: Articles 7, 12, 13 and 32 of Regulation (EU) 2016/679 and Article 5(3) of the ePrivacy Directive. Not a certification or legal assessment.

Priority findings

2 findings rated critical or high. Fix these first.

  1. Security headers

    Security headers are instructions your web server sends to every visitor’s browser. Missing ones leave visitors more exposed to attacks such as clickjacking and injected scripts.

    • High

      Missing X-Frame-Options header

      Prevents clickjacking attacks

      What to do: Add "X-Frame-Options: DENY" or "X-Frame-Options: SAMEORIGIN"

  2. GDPR outside view

    These are the privacy signals visitors and data protection authorities look for under GDPR.

    • High

      No Cookie Consent Banner found

      GDPR requires explicit consent for non-essential cookies

      What to do: Implement a cookie consent banner that appears on first visit

Need hands-on remediation? Email guard@offseq.com

Keep watching 1und1.de

This scan found 17 issues across 6 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

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Recommended

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  • TLS certificates and expiry
  • DNS records
  • SPF, DKIM and DMARC
  • Security headers
  • GDPR and NIS2 posture
  • Exposed services
  • Third-party trackers
  • Security score drift

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Results by check

Each check with its score, findings and the evidence it collected.

How this score is calculated

The security score runs 0–100, higher is better. It is the plain average of the security checks that completed in this scan, each counted equally. A check that could not run is left out: it counts neither as a pass nor as a fail.

Counted in this score

SSL/TLS
85
Security headers
65
Email security
70
DNS health
70
Network security
100
GDPR outside view
85
Average
79

Not counted

  • NIS2 outside view: Re-weights evidence from the TLS, email, DNS, network and hygiene checks, so counting it would count that evidence twice. Shown on its own.
  • OffSeq Observations: An AI reading of the site, useful context but not reproducible evidence. Shown on its own.

Findings that cap the score at 49

Each of these is serious on its own, so while any is present the site cannot rate better than high risk, however good the other checks are.

  • The certificate is not trusted by browsers
  • The website is not served over HTTPS
  • A database, remote desktop, file-sharing or Telnet service is reachable from the internet
  • The page loads a script from a compromised source
  • The domain registration has expired
  • SPF authorises every server to send mail as the domain

Partial scans

When the site blocks Guard or most checks cannot run, the score covers only the checks that ran (usually DNS and email), is capped at 75 and is shown as partial, without a risk level.

Risk levels

  • Critical0–25
  • High26–49
  • Medium50–75
  • Low76–100

Breach exposure

Leaked credentials and lookalike domains from OffSeq Breach. The counts are free; the detailed lists are paid add-ons.

Dark web exposure

Add-on

Leaked records that mention 1und1.de, from OffSeq Breach.

Total records
856,753
Employees
56
Customers
288,162
Third parties
568,535
Weak passwords
25%

Latest record dated 2026-06-05 · 274 subdomains affected

See the 10 newest leaked credentials

A one-off add-on to this report that lists the most recent identifier and password pairs OffSeq Breach holds for 1und1.de.

Select it in the checkout above.

Masked preview

  • –www.1und1.de2026-06-05
  • –www.1und1.de2026-06-02
  • –www.1und1.de2026-06-01
  • –1und1.de2026-05-29
  • –imap.1und1.de2026-05-29

Breach keeps ingesting new leaks, so these numbers can grow between scans.

Open in Breach(opens in a new tab)Monitor on Breach(opens in a new tab)

Technical appendix

Business context, site observations and technical notes gathered during the scan, and the standards behind each reference.

Business context

Business profile

1&1 Telecom GmbH holds a strong position in the German telecommunications market, offering bundled internet and mobile services with competitive pricing and a broad product portfolio including handsets and tablets. Their business model focuses on direct consumer sales and service provision, supported by a well-established brand and parent company backing. The company targets a wide audience, including private users and businesses, leveraging digital channels for customer engagement and service delivery. Partnerships with major technology and advertising platforms enhance their marketing reach. The website's content and structure indicate a mature digital strategy with emphasis on customer service and compliance, reflecting stable revenue streams and growth potential in a competitive industry.

Security posture

The website exhibits a solid security posture with mandatory HTTPS, secure data transmission, and use of security headers (though some could be more explicitly confirmed). The absence of exposed sensitive data and secure handling of form submissions reduce risk exposure. Integration of third-party scripts is managed carefully, but continuous monitoring is recommended to mitigate supply chain risks. The lack of a public security policy or incident response contact is a minor gap. GDPR compliance is evident, and the presence of a dedicated data protection officer contact enhances trust. Overall, the security maturity is high for a commercial telecommunications website, with room for improvement in transparency and vulnerability disclosure.

Recommendations

  1. Publish a dedicated security policy and incident response contact information to improve transparency.
  2. Implement and publicize a security.txt file to facilitate vulnerability reporting.
  3. Enhance explicit security headers such as X-Frame-Options and X-Content-Type-Options.
  4. Regularly audit and update third-party scripts to prevent supply chain vulnerabilities.
  5. Maintain and communicate clear data retention policies to strengthen privacy compliance.

Contact details published on the site

Addresses
Legal name
1&1 Telecom GmbH
VAT number
DE811160031
Registration number
HRB 12345
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
1&1 Telecom GmbH
Description
Die besten Angebote für Internet & Mobilfunk ➤ Günstige Tarife ✓ Handys & Tablets ✓ Highspeed Internet ✓ Top Service ➤ Jetzt bei 1&1 informieren!
Key services
Internet, Mobilfunk (mobile telephony), Handys & Tablets, Highspeed Internet
Content quality
excellent
Branding
consistent

Technology

Stack
JavaScript, XMLHttpRequest, Web Components, Google Tag Manager (utag.js), Tealium, Polymer Web Components polyfills
Frameworks
Polymer
Performance
moderate
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • Use of CSP and other security headers likely
  • No exposed sensitive data in HTML
  • Secure form submission via XMLHttpRequest with JSON payload

Analytics and tracking

Services
Tealium, Google Analytics (implied)
Tracking level
moderate
Privacy practices
good

Advertising

Ad networks
Google Adsense
Tracking pixels
Tealium
Marketing tools
Tealium
Transparency
good

Site quality

Design
excellent
User experience
excellent
Content relevance
excellent
Navigation
excellent
Professionalism
excellent
Trustworthiness
high

Key observations

  1. Website is professionally designed and well maintained.
  2. Comprehensive privacy and cookie policies with consent mechanisms are implemented.
  3. Use of modern web technologies and frameworks.
  4. Strong brand presence and consistent messaging.
  5. No signs of malicious or suspicious activity.
  6. Good SEO and accessibility practices observed.
Technical notes

Notes

The website is built on a modern technology stack including Polymer Web Components and Neos CMS, ensuring modularity and maintainability. Use of asynchronous JavaScript loading and preloading fonts indicates performance optimization efforts. The site integrates advanced tracking and marketing tools like Tealium and Google Tag Manager, supporting data-driven marketing. Mobile optimization and accessibility features are well implemented, contributing to a positive user experience. Hosting appears to be managed by the parent company or affiliated infrastructure, ensuring reliability. Some technical debt may exist in legacy polyfill usage, but overall the infrastructure supports scalability and security effectively.
Standards and sources

Reference chips under each finding point to the standard, regulation or specification the finding relates to. They are taken from the official datasets below and mapped conservatively: a finding with no defensible link shows none. NIS2 and GDPR references mark where a finding is relevant evidence, not a compliance verdict. Implementing Regulation (EU) 2024/2690 binds digital infrastructure and digital service providers; for other entities it is the most detailed public reading of the Article 21 measures. WCAG, EN 301 549, European Accessibility Act and Web Accessibility Directive references name the requirement an automated accessibility rule relates to; they are not a conformance verdict.

Retrieved 2026-10-25

Earlier scans of this domain

  1. 73/100Medium23 findingsView report
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